At a glance: IARC has classified red meat, night shift work, talc and glyphosate all as Group 2A — “probably carcinogenic to humans.” Red meat prompted revised dietary guidelines. Night shift work triggered compensation for Danish workers within a year. Talc entered a regulatory process that could lead to an EU cosmetics ban. Glyphosate got a $17-million-a-year industry campaign to “neutralize impact” instead — and New Zealand’s EPA has never reassessed it, most recently declining to do so in 2024.
The International Agency for Research on Cancer (IARC) has one job: assess whether something can cause cancer, and say so plainly.
Since 1965 it has run the same process on more than a thousand substances and exposures, sorting them into groups from “carcinogenic to humans” (Group 1) down to “probably not carcinogenic” (Group 4).
Group 2A — “probably carcinogenic to humans” — has been applied to red meat, to night shift work, to talc, and to glyphosate, the world’s most widely used herbicide and the active ingredient in Roundup. Three of those four classifications were followed by a regulatory or compensatory response within a few years. The fourth wasn’t.
This is what happened in each case, and what didn’t.
What Does IARC’s Group 2A Classification Mean?
Group 2A sits one rung below Group 1 (known human carcinogens like asbestos and tobacco smoke) and one above Group 2B (“possibly carcinogenic”). IARC assigns it when there is limited evidence of cancer in humans combined with sufficient evidence in animal studies, or strong mechanistic evidence. It’s a hazard classification — a statement about whether something can cause cancer under some circumstances — not a risk assessment of how likely that is for an individual at typical exposure levels.
That distinction matters, and IARC says so itself. But hazard classifications tend to have consequences all the same, because they’re usually the trigger that gets other agencies to look closer. Three cases below show what that looks like when it works as intended.
What Happened After IARC Classified Red Meat as a Carcinogen?
In October 2015, an IARC working group of 22 experts from 10 countries classified the consumption of red meat as probably carcinogenic to humans (Group 2A), citing limited evidence in humans and strong mechanistic evidence. Processed meat was placed in Group 1 — the same tier as asbestos — because the human evidence there was judged sufficient rather than limited.
IARC’s own director framed the finding as something meant to feed directly into policy: it would help governments balance risks and benefits and refine dietary advice. That’s roughly what happened. Health authorities in multiple countries — including New Zealand’s own dietary guidelines — folded the findings into revised advice recommending limits on processed meat and moderation of red meat intake. Cancer Research UK advised heavy red meat eaters to consider cutting down. France’s food safety agency recommended limiting meat consumption to 500 grams a week. The classification didn’t ban anything. It changed the advice millions of people are given about what’s on their plate.
What Happened After IARC Classified Night Shift Work?
IARC classified shift work involving circadian disruption as Group 2A in December 2007, placing it in the same category as anabolic steroids and UV radiation. The mechanism its scientists pointed to was disruption of melatonin production and circadian rhythm — biological plausibility that, combined with epidemiological signals in night shift nurses and flight attendants, was enough to clear the Group 2A bar.
Denmark didn’t wait for global consensus. The Occupational Diseases Committee reviewed the evidence within the same year, and by 2008 the Danish National Board of Industrial Injuries had formally recognised breast cancer from night shift work as an occupational disease. Women who had worked at least one night shift a week for twenty to thirty years and developed breast cancer began receiving compensation, paid through their employers’ industrial injuries insurance. Roughly 40 women received initial payments — many of them flight attendants for the airline SAS. The Danish National Board of Industrial Injuries was explicit that the IARC classification was a major trigger for the decision. It required strict qualifying criteria and wasn’t a ban on night shifts. But it was a government converting an IARC hazard finding into a compensation scheme for real, identifiable workers, within about a year of the classification.
Other bodies followed. The American Medical Association issued a policy statement recognising circadian disruption from occupational light exposure as a cancer risk. The UK’s Health and Safety Executive commissioned its own report. ISO 45001:2018, the international occupational health and safety standard, requires organisations to manage fatigue-related hazards including those from shift work, and in the US, OSHA’s General Duty Clause can require employers to address recognised, foreseeable workplace hazards of this kind.
To be fair to the sceptics: this wasn’t driven purely by the cancer classification. Shift work was already a recognised safety concern before IARC weighed in — fatigue and accident risk had generated sector-specific rules in aviation, trucking and rail for decades. What the 2007 classification did was add cancer risk to a pre-existing safety conversation and act as a catalyst. Regulators and employers expanded their obligations accordingly. Denmark didn’t wait for Group 1 certainty. It applied the precautionary principle and compensated the people who had already been harmed. Twelve years later, in 2019, IARC reviewed the evidence again and retained the Group 2A classification — it has now been upheld twice.
What Happened After IARC Classified Talc as a Carcinogen?
In July 2024, a working group of 29 scientists from 13 countries met at IARC’s Lyon headquarters and reclassified talc from “possibly carcinogenic” (Group 2B) to “probably carcinogenic to humans” (Group 2A), based on limited human evidence, sufficient evidence in animals, and strong mechanistic evidence. The concern centred on ovarian cancer risk from perineal use of talc-based body powder — the same exposure at the heart of tens of thousands of lawsuits against Johnson & Johnson.
Regulators moved fast. Two months later, in September 2024, the European Chemicals Agency’s Risk Assessment Committee adopted an opinion recommending that talc be classified as a Category 1B carcinogen under the EU’s CLP Regulation. Under that process, an RAC opinion must be formally adopted by the European Commission into CLP law before it carries binding legal force; once it is, Article 15 of the EU Cosmetics Regulation prohibits the use of CMR Category 1A, 1B or 2 substances in cosmetics unless a specific exemption is granted. Industry reporting at the time indicated an exemption application for talc had already been filed, with a cosmetics ban potentially taking effect as early as 2027 should that application fail. In the US, the FDA proposed a rule in December 2024 mandating asbestos testing for all talc-containing cosmetics. None of that erased the underlying scientific debate — IARC itself flagged contamination and methodology issues that complicate the picture — but the RAC opinion set a defined regulatory process in motion within months, not years.
What Happened After IARC Classified Glyphosate?
In March 2015, the same IARC Monographs Programme classified glyphosate as probably carcinogenic to humans (Group 2A) — based on limited evidence of cancer in humans, sufficient evidence in experimental animals, and strong evidence of genotoxicity for both pure glyphosate and its commercial formulations. The working group reviewed roughly a thousand studies to get there, a scale comparable to the red meat and talc reviews.
No public health guidance changed. No government compensation scheme opened. No phase-out process began. What did happen, within weeks, was different: Monsanto built a plan to make the finding go away.
By 2015, glyphosate had already been in US registration review since 2009, and independent researchers had already raised concerns that Roundup is more dangerous than glyphosate alone, with commercial formulations behaving differently to the isolated active ingredient in toxicity studies. The pre-existing momentum that turned the night-shift classification into action was arguably present here too — a panel of scientists from eleven countries had already flagged enough concern to justify the review. Instead of becoming a catalyst, the classification was treated as a problem to be managed.
The documentation for that is unusually direct, and it comes from Monsanto itself. In a January 2019 deposition tied to Roundup litigation, Monsanto public affairs director Sam Murphey testified under oath that in 2016 alone, the projects he was directly involved in ran to around $16–17 million — spending he tied to responding to the IARC classification, though he qualified that the figure covered broader glyphosate media and engagement work rather than IARC criticism alone. Notably, 2016 was also the year glyphosate’s EU licence was up for renewal and the US EPA was reviewing its registration — meaning the spending lined up precisely with the regulatory decisions Monsanto most needed to influence.
Internal company documents obtained through litigation and published by the investigative nonprofit US Right to Know show the strategy behind the money. A Monsanto public relations plan drawn up around the time of the classification assigned 20 corporate staffers to prepare for the IARC report, with stated objectives including “neutralize impact,” “establish public perspective on IARC,” “regulator outreach” and mobilising industry associations. The document also mapped out four tiers of external “industry partners” — pesticide and food lobby groups, and ostensibly independent commentary sites — recruited to carry Monsanto’s messaging without disclosing the source.
The tactics documented in discovery include a Forbes opinion piece criticising IARC that internal emails show was drafted inside Monsanto and passed to a Stanford fellow to publish under his own byline, and a Reuters investigation into IARC scientist Aaron Blair that Monsanto fed with a slide deck of talking points — later shown to promote a misleading account of the science. None of it changed the underlying evidence. What it changed was the public conversation about that evidence, for years.
Did Courts Find Glyphosate Causes Cancer?
Repeatedly, and expensively for Bayer, which bought Monsanto in 2018 along with its glyphosate liabilities. Juries have found for plaintiffs in the majority of Roundup trials that have gone the distance, including three verdicts exceeding US$1 billion — a Philadelphia jury awarded $2.25 billion in January 2024, and a Georgia jury awarded roughly $2.1 billion in March 2025 to a man who developed non-Hodgkin lymphoma after decades of Roundup use. More than 170,000 people in the US have filed claims. Bayer has now paid out around $11 billion resolving roughly 100,000 of them and, in February 2026, proposed a further $7.25 billion settlement fund to cover remaining and future non-Hodgkin lymphoma claims — all while continuing to argue publicly that regulators consider glyphosate safe.
That’s the strange position glyphosate now occupies: a company paying out billions in court for a cancer it insists, in the same breath, its product doesn’t cause. The litigation has exposed, in practical terms, what the precautionary principle was supposed to prevent — a foreseeable risk that was not disclosed, that people were left to discover through illness rather than warning.
Has New Zealand’s EPA Ever Reassessed Glyphosate?
Glyphosate has been sold and sprayed in New Zealand since the 1970s — before the Environmental Protection Authority (EPA) or the Hazardous Substances and New Organisms Act 1996 existed — and it has never undergone a full risk assessment here. In 2023, the Environmental Law Initiative (ELI) formally applied to the EPA for grounds to reassess glyphosate, citing new independent evidence including a meta-analysis showing a 41% increased risk of non-Hodgkin lymphoma among people exposed to glyphosate-based herbicides.
In July 2024 — almost a decade after IARC’s classification, and the same month IARC classified talc — the EPA declined. General Manager Chris Hill said the evidence submitted didn’t meet the threshold for “significant new information,” particularly when weighed against the findings of other international regulators. ELI took the decision to judicial review; in October 2025 the High Court found the EPA had not made a reviewable error, and by May 2026 ELI had withdrawn its appeal to the Court of Appeal. Glyphosate remains approved in more than 90 formulations for use on New Zealand roadsides, parks, farms and driveways, with no reassessment in sight and no timeline for one.
The gap shows up at ground level, too. Auckland Council has recorded six glyphosate exposure incidents among staff in two years, with no documented toxicological follow-up. Health New Zealand has confirmed it does not collect data on illnesses linked to glyphosate exposure, even in hospital settings — there is no surveillance system, no inter-agency reporting, and no national database tracking it. Asked who is responsible for monitoring glyphosate-related worker illness, MPI, WorkSafe, the EPA and the Ministry of Health each point to the others. It’s worth being precise about what that shows: it’s a documented accountability gap, not evidence of anyone’s intent. Nothing here demonstrates the EPA acted in bad faith or was captured by industry — only that, unlike Denmark, no one owns the problem.
Unlike France, Germany, Austria, the Netherlands, Belgium and Denmark — all of which restrict glyphosate use in public spaces or domestically — New Zealand has no such restriction. NZTA, DOC and most councils continue to use glyphosate-based herbicides on public land.
Why Did Glyphosate Get a Pass When the Others Didn’t?
Red meat: dietary guidelines updated. Night shift work: Danish workers compensated within a year, and the classification upheld again on review in 2019. Talc: cosmetics facing an EU ban and FDA testing rules within months. Glyphosate: a documented internal plan to “neutralize impact,” a $17-million-a-year PR effort, billions of dollars in jury verdicts — and a New Zealand regulator that, as recently as 2024, found no grounds to even take a fresh look.
It’s worth being careful about what explains that gap, because two different things are being compared here and they don’t carry the same weight of evidence. On the Monsanto side, the record is unusually explicit: sworn testimony, internal planning documents, a stated objective to “neutralize impact.” That’s documented intent. On the regulatory side — the EPA’s 2024 decision, the absence of a New Zealand surveillance system — what’s documented is an outcome, not a motive. The High Court found no reviewable legal error in the EPA’s process. Whether that outcome reflects an appropriately cautious regulator weighing conflicting international assessments, or a system structurally reluctant to act against an economically entrenched product, is a fair question to ask. It isn’t one this evidence, on its own, answers.
What isn’t in dispute is this: shift work has no manufacturer, no lobby group, and no marketing budget to defend. When IARC classified it Group 2A, there was no industry with a financial stake in the finding being ignored, and the workers affected had unions with standing to push for reform. Glyphosate is the world’s most widely used herbicide, built into the agricultural systems of multiple countries, backed by a manufacturer with the resources to contest, delay and reframe a finding that threatened continued approval — and regulatory systems, including New Zealand’s, that are explicitly designed to weigh economic benefit against risk. That’s not a conspiracy. It’s a structural asymmetry: the same hazard classification, filtered through very different economic stakes, produces very different regulatory appetite for action.
What Would Consistent Glyphosate Regulation Look Like in New Zealand?
None of this requires banning glyphosate. Denmark didn’t ban night shifts — it acknowledged the risk, compensated people already harmed, and put in place obligations to reduce future harm. That’s what applying the precautionary principle actually looks like, and it’s the low bar glyphosate hasn’t cleared in New Zealand:
- Health surveillance for workers who handle glyphosate regularly, comparable to the occupational monitoring shift workers receive in countries that took the 2007 classification seriously.
- Mandatory follow-up on exposure incidents — the kind absent after all six recorded incidents at Auckland Council.
- A functioning national tracking system, so agencies aren’t left pointing at each other when asked who is responsible.
- Warning labels that acknowledge the IARC classification and the ongoing scientific debate.
- A reassessment, at minimum, so the question can be examined on the current evidence rather than closed on a decade-old threshold.
The classification was the same each time: Group 2A, probably carcinogenic to humans, decided by the same agency using the same methodology. Three prompted regulatory or public health action. One prompted a documented $17 million campaign to minimise the impact of the IARC classification.
If Group 2A was good enough to compensate Danish flight attendants within a year, it’s a fair question why it hasn’t been enough, a decade on, to put a warning label on a bottle of Roundup sold in New Zealand.
Further Reading
Denmark Compensates Women Who Developed Cancer After Night Shifts — CBC News, 2009 — the original reporting on Denmark’s landmark decision. cbc.ca
IARC Retains “Probably Carcinogenic” Classification for Night Shift Work — ISGlobal, 2019 — what the second evaluation found and why the classification held. isglobal.org
Secret Documents Expose Monsanto’s War on Cancer Scientists — U.S. Right to Know — the fuller picture of Monsanto’s ghostwriting, front groups and media strategy. usrtk.org
Glyphosate Science Denial: How Monsanto Shaped the Record — U.S. Right to Know — how Monsanto worked to ghostwrite papers and shape the regulatory record. usrtk.org
Challenging the EPA’s Regulatory Failure on Glyphosate — Environmental Law Initiative — the full case timeline of ELI’s attempt to force a New Zealand reassessment. eli.org.nz
Sprayed, Splashed, Soaked: Auckland Council’s Glyphosate Exposure Incidents — No More Glyphosate NZ — six documented exposure incidents, zero toxicological follow-up. nomoreglyphosate.nz
Why NZ’s Health System Can’t Track Glyphosate Exposure — No More Glyphosate NZ — no surveillance system, no inter-agency reporting, no national database. nomoreglyphosate.nz
Glyphosate Health Risks: Who’s Responsible? — No More Glyphosate NZ — mapping the accountability gap between MPI, WorkSafe, the EPA and the Ministry of Health. nomoreglyphosate.nz
Bayer’s Roundup Legal Woes — No More Glyphosate NZ — tracking the lawsuits and settlement figures as they’ve developed. nomoreglyphosate.nz
Roundup vs Glyphosate: Why the Formulation Matters — No More Glyphosate NZ — the toxicity concerns specific to commercial formulations rather than the isolated active ingredient. nomoreglyphosate.nz
Glyphosate vs Roundup: The Warning Label Gap — No More Glyphosate NZ — what a warning label acknowledging the IARC classification would actually look like. nomoreglyphosate.nz
Between the science and the spin sits a fairly simple question New Zealanders can still ask their councils and their EPA: if red meat, night shift work and talc all got a second look after a Group 2A rating, why hasn’t glyphosate?
Frequently Asked Questions
What is IARC’s Group 2A cancer classification?
Group 2A means IARC has found limited evidence of cancer in humans combined with sufficient evidence in animal studies, or strong mechanistic evidence. It sits one tier below Group 1 (known carcinogens like asbestos and tobacco) and one above Group 2B (“possibly carcinogenic”). It’s a hazard classification, not a measure of individual risk at typical exposure levels.
Is glyphosate classified as a carcinogen?
Yes. IARC classified glyphosate as Group 2A, “probably carcinogenic to humans,” in March 2015, based on limited human evidence, sufficient animal evidence, and strong evidence of genotoxicity. The US EPA and other regulators have reached different conclusions using risk-assessment rather than hazard-classification methodology.
How much did Monsanto spend fighting the IARC glyphosate ruling?
Monsanto public affairs director Sam Murphey testified under oath in a January 2019 deposition that projects he was directly involved in ran to roughly $16–17 million in 2016 alone, tied to responding to the IARC classification. Internal documents show a stated objective to “neutralize impact.”
Did Denmark compensate night shift workers for cancer?
Yes. Within a year of IARC’s 2007 Group 2A classification of night shift work, Denmark’s National Board of Industrial Injuries began compensating women who developed breast cancer after twenty-plus years of weekly night shifts. Around 40 women, many of them flight attendants, received payouts through their employers’ insurance.
Has New Zealand’s EPA reassessed glyphosate?
No. The Environmental Law Initiative applied for grounds to reassess glyphosate in 2023; the EPA declined in July 2024, stating the evidence didn’t meet the threshold for “significant new information.” The High Court upheld that decision in October 2025, and ELI withdrew its appeal in May 2026. Glyphosate remains approved in more than 90 formulations for use in New Zealand.
Why hasn’t glyphosate been restricted like talc or red meat?
Unlike red meat, night shift work or talc, glyphosate has historically been backed by major manufacturers with a direct financial stake in the classification being ignored, and regulatory systems — including New Zealand’s — that are structured to weigh economic benefit against risk. Documented Monsanto planning to “neutralize impact” is the clearest evidence for that difference; the absence of New Zealand regulatory action is a documented outcome, not proof of intent.
Image Source & Attribution
The feature image on this page was created using AI-assisted image generation from an original concept developed by No More Glyphosate NZ and refined for publication in Canva.
For articles like this, finding a suitable stock image can be surprisingly difficult. This story isn’t about a single person, place or product — it’s about how different regulatory responses can follow the same scientific classification. Rather than using a generic or potentially misleading stock photograph, we chose to create a conceptual illustration that more accurately represents the central theme of the article.
AI is a useful creative tool for visualising ideas that are otherwise difficult or impossible to photograph, allowing us to illustrate complex concepts without compromising the accuracy of the story itself.
